I can see a lot of improvement, but the folds still need a lot of work; the shading is a bit blocky. Large dolls are hard to doll on; it's better to doll on small bases in order to get the hang of it. Blood-cocoa on DA has some great small bases, as does Kawaii Hannah. Their links are in the bases section.

It's the hair that needs the most work; I can sympathise with that, as I find shading hair very difficult. X_x

WOW! Your skirt shading has improved so much! Did you follow a tutorial?

The shirt is a little pillowy and the hair needs a little work (you need more shadows and highlights etc... look at different dolls and follow different tutorials on places such as deviantArt to see which methods you like the best) but judging on your progress, I think you could be a really excellent doller if you put your mind to it and with a little more practice. :]

EDIT: You forgot the base credit. That one's from Megan Clare's site isn't it?